Effect of ultrasonic field on electrodeposition preparation of Zn anode and research on the battery performance

Due to high safety and environmental friendliness, aqueous Zn-ion batteries exhibit significant potential. However, during the electrodeposition process of Zn anode, dendrite formation and hydrogen evolution occur, which significantly deteriorate the performance of batteries. The unique cavitation effect of ultrasonic field significantly regulates the electrodeposition process of Zn²⁺ in the solution. In this paper, the surface morphology of Zn anode was observed, and the electrochemical techniques were employed to characterize the electrochemical behavior of electrodeposited Zn in a weakly acidic sulfate system under varying ultrasonic powers. The prepared Zn anode was assembled into Zn||AC full cell for tests, and the preferred orientation in Zn anode after cycling was characterized. The research shows that under the static condition, the surface presents a 3D stacked structure of hexagonal Zn flakes with disordered morphology. Under the ultrasonic field, stacking direction of hexagonal Zn flakes becomes more ordered, and the lamellae are more tightly packed. In particular, when the ultrasonic power is 70 W, Zn anode exhibits better electrochemical performance, meanwhile, the cell shows a higher Coulombic efficiency. After 1500 cycles, the Zn (002) crystal plane proportion of Zn anode prepared at 70 W is much higher.